|
document - world document handle, from LoadWorldDocument or CreateWorldDocument redo (optional) - True to preview the next redo; False to preview the next undo (default) |
|
Returns the world's text as the next undo (or redo) would leave it, changing nothing. Look before you leap: an editor can check that an undo would not remove or change something that is locked or selected, before it sends the undo with EditWorldDocumentWorkspace at the same expected revision. Returns "" when there is no step to take, when the world has no workspace, or when the step cannot be taken; WorldDocumentError() then says why. For the full story - the edit protocol, Save All, recovery, export plans and limits - see the Saving and exporting resource projects guide. See also: WorldDocumentWorkspaceHistory, EditWorldDocumentWorkspace, WorldDocumentJson. |
; OpenWorldDocumentWorkspace Example
; ----------------------------------
; Everything here happens in memory: no file is written
world=LoadWorldDocument("../../../samples/courtyard/courtyard.world")
If world=0 Then RuntimeError WorldDocumentError()
If Not OpenWorldDocumentWorkspace(world) Then RuntimeError WorldDocumentError()
stone_file$="../../../samples/courtyard/stone.material"
; The report lists the world and every resource it uses
report=WorldDocumentWorkspaceJson(world)
documents=JsonObjectGet(report,"documents")
Print "Workspace revision "+WorldDocumentWorkspaceRevision(world)+": "+JsonCount(documents)+" documents"
FreeJson documents
FreeJson report
; Warm up the stone material, starting from its staged text...
staged=LoadWorldResourceDocument(world,stone_file)
stone=ResourceDocumentJson(staged)
FreeResourceDocument staged
definition=JsonObjectGet(stone,"definition")
colour=ParseJson("[0.95,0.6,0.4,1]")
JsonObjectSet definition,"color",colour
JsonObjectSet stone,"definition",definition
stone_text=CreateJsonString(JsonStringify(stone))
FreeJson colour
FreeJson definition
FreeJson stone
; ...and give the world a new name
scene=WorldDocumentJson(world)
name=CreateJsonString("Warm courtyard")
JsonObjectSet scene,"name",name
scene_text=CreateJsonString(JsonStringify(scene))
FreeJson name
FreeJson scene
; One edit changes both; a fresh workspace has every document at revision 1
text$="{'protocol':'blitz3d.document-workspace-edit','version':1,'operation':'edit',"
text=text+"'label':'Warm up the courtyard','expectedRevision':"+WorldDocumentWorkspaceRevision(world)+","
text=text+"'changes':[{'path':'stone.material','revision':1},{'path':'courtyard.world','revision':1}]}"
edit=ParseJson(Replace(text,"'",Chr(34)))
changes=JsonObjectGet(edit,"changes")
For index=0 To 1
change=JsonArrayGet(changes,index)
If index=0 Then JsonObjectSet change,"source",stone_text Else JsonObjectSet change,"source",scene_text
JsonArraySet changes,index,change
FreeJson change
Next
JsonObjectSet edit,"changes",changes
If Not EditWorldDocumentWorkspace(world,edit) Then RuntimeError WorldDocumentError()
FreeJson changes
FreeJson edit
FreeJson scene_text
FreeJson stone_text
Print "After the edit, revision "+WorldDocumentWorkspaceRevision(world)+"; undo would undo '"+WorldDocumentWorkspaceHistory(world)+"'"
; Opening the material again reads the staged text, not the file
staged=LoadWorldResourceDocument(world,stone_file)
stone=ResourceDocumentJson(staged)
definition=JsonObjectGet(stone,"definition")
colour=JsonObjectGet(definition,"color")
Print "The staged stone colour is "+JsonStringify(colour,0)
FreeJson colour
FreeJson definition
FreeJson stone
FreeResourceDocument staged
; Preview the world that undo would give back, changing nothing
preview=ParseJson(WorldDocumentWorkspaceUndoSource(world))
old_name=JsonObjectGet(preview,"name")
Print "Undo would bring back the name '"+JsonText(old_name)+"'"
FreeJson old_name
FreeJson preview
; Undo is an edit too, checked against the current revision
text="{'protocol':'blitz3d.document-workspace-edit','version':1,'operation':'undo','expectedRevision':"
undo=ParseJson(Replace(text,"'",Chr(34))+WorldDocumentWorkspaceRevision(world)+"}")
If Not EditWorldDocumentWorkspace(world,undo) Then RuntimeError WorldDocumentError()
FreeJson undo
Print "After undo, redo would redo '"+WorldDocumentWorkspaceHistory(world,True)+"'"
FreeWorldDocument world
Print ""
Print "Press any key to close the example"
WaitKey
End